[Paleontology • 2017] Aphaneramma gavialimimus • A New Extreme Longirostrine Temnospondyl from the Triassic of Madagascar: Phylogenetic and Palaeobiogeographical Implications for Trematosaurids ---ScRaBBlE

Aphaneramma gavialimimus Fortuny, Gastou, Escuillié, Ranivoharimanana & Steyer, 2017

 DOI: 10.1080/14772019.2017.1335805   Life reconstruction by Marc Boulay | @JournalSystPal 

Aphaneramma gavialimimus

Fortuny, Gastou, Escuillié, Ranivoharimanana & Steyer, 2017

 DOI: 10.1080/14772019.2017.1335805 
  @JournalSystPal 

Abstract

Trematosaurids form a very large and remarkable clade of Triassic tetrapods (Temnospondyli: Stereospondyli) with a worldwide geographical distribution. Compared with specimens from Europe, Australia or North America, they remain relatively scarce in African rocks, where they are mainly known in the Early Triassic of Madagascar and South Africa. Longirostrine trematosaurids were only known from Madagascar, represented by the genus Wantzosaurus. However, we describe herein a new species of the longirostrine trematosaurid Aphaneramma, Aphaneramma gavialimimus sp. nov., from the Olenekian (Lower Triassic) of Madagascar. This genus was previously known from the Early Triassic of Europe and Asia. Based on a new nearly complete skull, the new species is characterized by a premaxilla-nasal suture anteriorly directed, not contacting the nostrils; choanae completely included within the palatines; the ventral opening of the orbits in the anterior part of the interpterygoid vacuities; a very elongated nasal covering more than 50% of the prenarial length; and an anteriorly widened cultriform process. Aphaneramma gavialimimus sp. nov., with a skull length of about 40 cm, may be one of the largest known trematosaurids. Its inclusion in a new phylogenetic analysis confirms its close affinities with the North American genus Cosgriffius, and clarifies the relationships of trematosaurids in general and lonchorhynchines in particular. The new species also increases the palaeobiodiversity of marine trematosaurs in Gondwana and allows discussing their apparently rapid cosmopolitanism just after the great Permian–Triassic mass extinction.

Keywords: Lonchorhynchinae, Olenekian, palaeobiogeography, Permian–Triassic mass extinction

Figure 1. Aphaneramma gavialimimus sp. nov., Lower Triassic of Madagascar in dorsal view. A, photograph of the holotype UAAmb007; B, photograph of the plastotype MNHN-6703; C, interpretative drawing. 

Systematic palaeontology

Temnospondyli Zittel, 1888

Stereospondyli Zittel, 1888

Trematosauria Romer, 1947 sensu Yates & Warren, 2000

Trematosauroidea Säve-Söderbergh, 1935 sensu Schoch, 2013

Family Trematosauridae Watson, 1919

Subfamily Lonchorhynchinae Säve-Söderbergh, 1935 sensu Steyer, 2002

Aphaneramma Smith Woodward, 1904

Type species. Aphaneramma rostratum Smith Woodward, 1904

(D ‘Lonchorhynchus obergi’ Wiman, 1910) from the early Olenekian of the Sticky Keep of Spitsbergen, Vikinghøgda Formation, Svalbard Archipelago, Norway.

Definition. All taxa sharing a more recent common ancestor with Aphaneramma rostratum than with Cosgriffius campi.

Aphaneramma gavialimimus sp. nov. 

 Etymology. Imitates a gharial (Gavialis gangeticus), due to the general shape similarity with this hyper-longirostral taxon.

Aphaneramma gavialimimus sp. nov., Lower Triassic of Madagascar.

 Life reconstruction by Marc Boulay  (MarcBoulay.fr). 

Josep Fortuny, Stéphanie Gastou, François Escuillié, Lovasoa Ranivoharimanana and J.-Sébastien Steyer. 2017. A New Extreme Longirostrine Temnospondyl from the Triassic of Madagascar: Phylogenetic and Palaeobiogeographical Implications for Trematosaurids. Journal of Systematic Palaeontology.   DOI: 10.1080/14772019.2017.1335805  

twitter.com/JournalSystPal/status/881839746095427585

 facebook.com/media/set/?set=a.1824313547882176&type=3

  

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

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شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[PaleoMammalogy • 2017] Xibalbaonyx oviceps • A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance ---ScRaBBlE

Xibalbaonyx oviceps 

Stinnesbeck, Frey, Olguín, Stinnesbeck, Zell, Mallison, González, Núñez, Morlet, Mata, Sanvicente, Hering & Sandoval, 2017.

 DOI: 10.1007/s12542-017-0349-5 

Abstract

Here we describe a new genus and species of giant ground sloth, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), from the drowned cave system of the northeastern Yucatán Peninsula. The specimen is Late Pleistocene in age and was discovered in the Zapote sinkhole (cenote) near Puerto Morelos in the Mexican state of Quintana Roo. Xibalbaonyx oviceps differs significantly from all hitherto known Megalonychidae including those from the Greater Antilles and South America. The new taxon suggests a local Caribbean radiation of ground sloths during the Late Pleistocene, which is consistent with the dispersal of the group along a Mexican corridor.

Keywords: Ground sloths, Pleistocene, Yucatán Peninsula, Mexico 

Systematic palaeontology

Superorder Xenarthra Cope, 1889

Order Pilosa Flower, 1883

Superfamily Megatherioidea Gray, 1821

Family Megalonychidae Gervais, 1855

Diagnosis of the family. Xibalbaonyx oviceps is identified as a member of Megalonychidae based on the following features: dorsal contour of skull evenly convex in lateral view. The glenoid fossa is mediolaterally widened, its posterior surface smooth and the fossa is well separated from the porus acusticus. The lateral plate of the entotympanic is thin with a medial expansion and weak participation in the floor of the tympanic cavity. The paroccipital process is well developed (Patterson et al. 1992; Gaudin 1995, 2004; McDonald et al. 2013b).

Fig. 4: Xibalbaonyx oviceps (Za2014-01) skull in lateral view (left side). 

Fig. 3: Xibalbaonyx oviceps in situ within the Zapote cenote; Skull and mandible (Za2014-01, -05)

Xibalbaonyx oviceps gen. et sp. nov.

Etymology. For the genus: Xibalbá = Maya for “underground” or “place of fear,” dedicated to the cave divers who dive into the “underworld,” the cenotes, and collect the fossils under risky conditions, but also in honor of the Yucatán Peninsula, which is also called the Maya region; “őνυξ” (onyx) = Greek for “claw” or “finger nail;” for the species: oviceps from ovum = Latin for “egg” and caput = “head,” “egghead,” referring to the regularly domed skull roof of the specimen.

Stratigraphic and geographic distribution. The Cenote Zapote 16 Q 0486971 UTM 2305968, Ruta de los Cenotes Puerto Morelos Quintana Roo, Mexico. Late Pleistocene and/or Early Holocene (9.305 ± 35 14C bp, 10.647–10.305 cal bp).

.....

 Conclusions: 

The well-preserved skull and mandible of a ground sloth discovered in the Zapote cenote Cave near Puerto Morelos on the northeastern Yucatán Peninsula of Mexico is here described as a new genus and species of Megalonychidae. The individual, here named Xibalbaonyx oviceps, has a dental formula of 5/4 including a greatly enlarged caniniform tooth of triangular cross-section. This caniniform is separated by a long diastema from the molariform tooth rows in both the lower and upper jaw. The molariform teeth show oval, rounded rectangular to reniform (McDonald et al. 2013b) occlusal shapes with transverse crests. All teeth except for the upper caniniforms, show striations and apicobasal sulci that may be expressed as shallow grooves or deep sulci. The ascending process of the jugal is longer than the descending and middle process of the jugal. The pterygoids are inflated. The glenoid fossa is transversally widened. The skull is elongated and narrow, with a nasional impression on the nasals. The temporal lines are widely separated and do not form a sagittal crest. The skull is narrow and gracile compared that of other Megalonychidae of similar size, such as Megalonyx or Ahytherium. The Zapote ground sloth was a subadult individual, based on the degree of suture fusion in the skull, faint temporal lines and the condition of the occlusion faces of the molariforms. To present knowledge Xibalbaonyx appears to have been endemic on the Yucatán Peninsula, suggesting a local microevolution on this karst desert during the Late Pleistocene.

Sarah R. Stinnesbeck, Eberhard Frey, Jerónimo Avíles Olguín, Wolfgang Stinnesbeck, Patrick Zell, Heinrich Mallison, Arturo González González, Eugenio Aceves Núñez, Adriana Velázquez Morlet, Alejandro Terrazas Mata, Martha Benavente Sanvicente, Fabio Hering and Carmen Rojas Sandoval. 2017. Xibalbaonyx oviceps, A New Megalonychid Ground Sloth (Folivora, Xenarthra) from the Late Pleistocene of the Yucatán Peninsula, Mexico, and Its Paleobiogeographic Significance. PalZ [Paläontologische Zeitschrift]. 91(2); 245–271.   DOI: 10.1007/s12542-017-0349-5

ResearchGate.net/publication/317185046_Xibalbaonyx_oviceps_a_new_megalonychid_ground_sloth_Folivora_Xenarthra_from_the_Late_Pleistocene_of_the_Yucatan_Peninsula_Mexico_and_its_paleobiogeographic_significance

Ancient species of giant sloth discovered in Mexico  ctv.news/M8rqjqN

Tízezer éve élt óriáslajhár maradványaira bukkantak Mexikóban http://www.origo.hu/tudomany/20170817-archeologia-tizezer-eve-elt-oriaslajhar-maradvanyaira-bukkantak-mexikoban.html

Kurzfassung: Die Unterwasserhöhlen auf der nordöstlichen Halbinsel Yukatan zeigen eine artenreiche Ansammlung von Großsäugern aus dem späten Pleistozän und frühen Holozän. Hier beschreiben wir die neue Gattung und Art eines Riesenfaultiers, Xibalbaonyx oviceps (Megalonychidae, Xenarthra), aus der Zapote Doline (Cenote) in der Nähe von Puerto Morelos im mexikanischen Bundesstaat Quintana Roo. Das Exemplar unterscheidet sich signifikant von allen bisher dokumentierten Megalonychidae einschließlich derjenigen von den Großen Antillen und aus Südamerika. Das neue Taxon deutet auf eine lokale karibische Radiation von Bodenfaultieren währen des Spätpleistozäns hin, die mit der Ausbreitung der Gruppe entlang des mexikanischen Korridors übereinstimmt.

Schlüsselwörter: Bodenfaultiere Pleistozän Yukatan Halbinsel Mexiko 

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

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شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[PaleoOrnithology • 2017] An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia ---ScRaBBlE

An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia. 

Zelenkov, Averianov & Popov, 2017

elementy.ru   Illustration: Andrey Atuchin 

Abstract

Ornithuromorph birds (the clade which includes modern avian radiation) first appeared in the Early Cretaceous in Asia and achieved a great diversity during the latest ages of the Late Cretaceous (Campanian and Maastrichtian). The evolutionary history of orithuromorphs during the first 17 MYAs of the Late Cretaceous (Cenomanian to Santonian ages) remains very poorly known, as the fossil record for this time interval is largely restricted to several isolated finds of the classic avian genus Ichthyornis in North America. Here we describe an isolated distal tibiotarsus of an evolutionary advanced bird, morphologically similar to Ichthyornis, from the middle Cenomanian of Saratov Province, European Russia. This is the first documentation of an Ichthyornis-like bird in the Old World. The find further constitutes only the second pre-Campanian record of the Late Cretaceous Ornithuromorpha in Eurasia, the second record of Cenomanian birds in Russia. This discovery shows that Ichthyornis-like birds enjoyed a wide geographical distribution as early as the beginning of the Late Cretaceous. Given that the earliest and the most primitive ornithuromorph birds are known from Asia, the new find supports a Eurasian origin for Ichthyornithidae.

Keywords: Cenomanian; East Europe; Ornithuromorpha; Palaeobiogeography

Systematic paleontology

Aves Linnaeus 1758

Ornithuromorpha Chiappe et al. 1999

Ornithurae Haeckel 1866

?Ichthyornithidae Marsh 1873

Gen. et sp. indet.

Material. Specimen PIN 5554/1, distal fragment of a right tibiotarsus.

Locality and horizon. Site SNB-2a, Nizhnyaya Bannovka, Krasnoarmeisk District, Saratov Province, Russia; Middle Member, Melovatka Formation, middle Cenomanian, lower Upper Cretaceous.

Fig. 2. Specimen PIN 5554/1, distal tibiotarsus of an Ichthyornis-like bird from the middle Cenomanian of European Russia. A, lateral view; B, cranial view; C, medial view; D, caudal view; E, proximal view; F, distal view; G, interpretative drawing of the cranial view.

Abbreviations: cl, condylus lateralis; cm, condylus medialis; conc, concavity; csic, concavities within sulcus intercondylaris; ?dep, depression; em, epicondylus medialis; sic, sulcus intercondylaris; se, sulcus extensorius; tub, tuberosity. 

DOI: 10.1016/j.cretres.2017.03.011

Conclusions

A partial tibiotarsus from the middle Cenomanian of the Nizhnyaya Bannovka locality in Saratov Province (European Russia) belongs to an evolutionary advanced ornithuromorph bird, similar in size and morphology to the North American Ichthyornis. This is the first reliable documentation of Ichthyornis-like birds in the Old World, because previously referred specimens indeed belong to Enantiornithes. This discovery confirms a wide geographic distribution of Ichthyornis-like birds already in the beginning of the Late Cretaceous and supports the Eurasian origin of Ichthyornithidae. The new specimen is further the first pre-Campanian Late Cretaceous ornithuromorph bird in Eurasian known from postcranial material.

Nikita V. Zelenkov, Alexander O. Averianov and Evgeny V. Popov. 2017. An Ichthyornis-like bird from the earliest Late Cretaceous (Cenomanian) of European Russia.
 Cretaceous Research. 75; 94–100. DOI: 10.1016/j.cretres.2017.03.011

Поволжский ихтиорнис • Никита Зеленков • Научная картинка дня на «Элементах» • Палеонтология https://elementy.ru/kartinka_dnya/307/Povolzhskiy_ikhtiornis

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[PaleoIchthyology • 2017] Eoanabas thibetana • Fossil Climbing Perch and Associated Plant Megafossils indicate A Warm and Wet Central Tibet During the late Oligocene ---ScRaBBlE

Eoanabas thibetana

Wu, Miao, Chang, Shi & Wang, 2017

  DOI: 10.1038/s41598-017-00928-9  IVPP.cas.cn 

Abstract

Understanding the Tibetan Plateau’s palaeogeography and palaeoenvironment is critical for reconstructing Asia’s climatic history; however, aspects of the plateau’s uplift history remain unclear. Here, we report a fossil biota that sheds new light on these issues. It comprises a fossil climbing perch (Anabantidae) and a diverse subtropical fossil flora from the Chattian (late Oligocene) of central Tibet. The fish, Eoanabas thibetana gen. et sp. nov., is inferred to be closely related to extant climbing perches from tropical lowlands in south Asia and sub-Saharan Africa. It has osteological correlates of a labyrinth organ, which in extant climbing perches gives them the ability to breathe air to survive warm, oxygen-poor stagnant waters or overland excursion under moist condition. This indicates that Eoanabas likewise lived in a warm and humid environment as suggested by the co-existing plant assemblage including palms and golden rain trees among others. As a palaeoaltimeter, this fossil biota suggests an elevation of ca. 1,000 m. These inferences conflict with conclusions of a high and dry Tibet claimed by some recent and influential palaeoaltimetry studies. Our discovery prompts critical re-evaluation of prevailing uplift models of the plateau and their temporal relationships with the Cenozoic climatic changes.

Systematic Palaeontology  

Teleostei Müller, 1845

Anabantiformes sensu Wiley and Johnson, 2010

Anabantoidei sensu Lauder and Liem, 1983

Anabantidae Bonaparte, 1839

Eoanabas thibetana gen. et sp. nov.

Etymology. The generic name combines ‘Eo-’ (Greek, early/primeval) with ‘Anabas’, the type genus of Anabantidae from tropical Asia. The specific name refers to Tibet, China.

Holotype. IVPP V 22782, a complete skeleton, part and counterpart (Fig. 1a,b).

Paratypes. Sixteen specimens are designated as paratypes (Supplementary Information).

Locality and Horizon. Jiangnongtangga (type locality) and Songwori in south Nima Basin and Dayu in Lunpola Basin in central Tibet (Supplementary Figs 1 and 2). Middle-upper part of Dingqing Formation, late Oligocene (Chattian) (ca. 26~23.5 Ma)6, 20, 26.

Diagnosis. A labyrinth fish displaying anabantid characteristics including a posterior notch of the opercle bounded by spines, a V-shaped strut on inner side of opercle and six to nine anal-fin spines. It shares with Asian anabantids the following derived characters: broad infraorbitals 3–5 completely covering the cheek, a sensory canal pore just behind sphenotic/pterotic junction and pelvic plate lying flat; and it shares with African anabantids some derived characters, e.g., sensory canal opening in between the infraorbitals, supraorbital commissure of the sensory canal absent and male postocular contact organ present.

Figure 1 A new fossil climbing perch, Eoanabas thibetana gen. et sp. nov. from the upper Oligocene of central Tibet. It resembles its extant tropical relatives in having a labyrinth organ for air breathing and postocular contact organ in male fishes for stimulating the female during a mating clasp.
(a) Photograph and (b) line drawing of holotype (IVPP V22782a), image horizontally rotated. (c) Photograph and (d) line drawing of the head of IVPP V18412a, red area in (d) representing muscular attachment facet.

Abbreviations: alm, attachment facet of levator operculi muscle; Cbr1, ceratobranchial of first gill arch; op.st, V-shaped struts on inner side of opercles.

Figure 2 Fossil climbing perch, Eoanabas thibetana gen. et sp. nov. from the upper Oligocene of central Tibet.
(a) Line drawing of the head of IVPP V18414a. (b) Photograph of IVPP V18414a. (c) Photograph of IVPP V18581a. (d) Scanning Electron Microscope (SEM) images of relics of labyrinth organ in (c), arrows pointing the pores on the lamellae. (e) Computerized tomography of labyrinth organ (lateral view) of Anabas testudineus (OP 435). (f) Cleared and stained head showing the labyrinth organ and associated structures of Anabas testudineus (collection no. OP 432). (g) Cleared and stained specimen of Anabas testudineus (collection no. OP 433). (h) Osteological restoration of Eoanabas, purported male; not to scale.

Images in (c), (d) are horizontally rotated. Abbreviations: br, branchiostegal rays; hp1, hypural 1; m., muscle; php, parhypural.

Feixiang Wu, Desui Miao, Mee-mann Chang, Gongle Shi and Ning Wang. 2017. Fossil Climbing Perch and Associated Plant Megafossils indicate A Warm and Wet Central Tibet During the late Oligocene. Scientific Reports. 7, Article number: 878.  DOI: 10.1038/s41598-017-00928-9 
ResearchGate.net/publication/316090334_Fossil_climbing_perch_and_associated_plant_megafossils_indicate_a_warm_and_wet_central_Tibet_during_the_late_Oligocene

IVPP.cas.cn/xwdt/tpxw/201706/t20170605_4807953.html

Feixiang Wu, Dekui He, Mee-mann Chang and Desui Miao. 2017. New light on the paleobiogeography of the labyrinth fishes. RESEARCH & KNOWLEDGE. 3(2); 63-64. DOI: 10.14456/randk.2017.29
 rk.msu.ac.th/wp-content/uploads/2017/09/14-Feixiang.pdf

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

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شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2017] Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s First Named Cretaceous Sauropod Dinosaur ---ScRaBBlE

Reconstruction of the possible sequence of events that led to the preservation of the carcass of the sauropod Austrosaurus mckillopi in the Eromanga Sea.
(A) Austrosaurus as a living animal on land; (B) freshly deceased Austrosaurus prior to bloating; (C) bloated Austrosaurus carcass washed out to sea, where it was possibly scavenged by marine reptiles like Kronosaurus; (D) the partially defleshed but still effectively intact thoracic portion of the Austrosaurus carcass is picked at by sharks as it sinks to the seafloor; (E) the thoracic portion of the Austrosaurus carcass is buried along with several ammonites (Beudanticeras) and bivalves (Inoceramus), which were possibly drawn to the carcass as it decayed.

Reconstruction by Travis R. Tischler.

 Poropat, Nair, Syme, et al. 2017. Reappraisal of Austrosaurus mckillopi Longman, 1933. ... DOI: 10.1080/03115518.2017.1334826

Austrosaurus mckillopi was the first Cretaceous sauropod reported from Australia, and the first Cretaceous dinosaur reported from Queensland (northeast Australia). This sauropod taxon was established on the basis of several fragmentary presacral vertebrae (QM F2316) derived from the uppermost Lower Cretaceous (upper Albian) Allaru Mudstone, at a locality situated 77 km west-northwest of Richmond, Queensland. Prior to its rediscovery in 2014, the type site was considered lost after failed attempts to relocate it in the 1970s. Excavations at the site in 2014 and 2015 led to the recovery of several partial dorsal ribs and fragments of presacral vertebrae, all of which clearly pertained to a single sauropod dinosaur. The discovery of new material of the type individual of Austrosaurus mckillopi, in tandem with a reassessment of the material collected in the 1930s, has facilitated the rearticulation of the specimen. The resultant vertebral series comprises six presacral vertebrae—the posteriormost cervical and five anteriormost dorsals—in association with five left dorsal ribs and one right one. The fragmentary nature of the type specimen has historically hindered assessments of the phylogenetic affinities of Austrosaurus, as has the fact that these evaluations were often based on a subset of the type material. The reappraisal of the type series of Austrosaurus presented herein, on the basis of both external morphology and internal morphology visualized through CT data, validates it as a diagnostic titanosauriform taxon, tentatively placed in Somphospondyli, and characterized by the possession of an accessory lateral pneumatic foramen on dorsal vertebra I (a feature that appears to be autapomorphic) and by the presence of a robust ventral mid-line ridge on the centra of dorsal vertebrae I and II. The interpretation of the anteriormost preserved vertebra in Austrosaurus as a posterior cervical has also prompted the re-evaluation of an isolated, partial, posterior cervical vertebra (QM F6142, the ‘Hughenden sauropod’) from the upper Albian Toolebuc Formation (which underlies the Allaru Mudstone). Although this vertebra preserves an apparent unique character of its own (a spinopostzygapophyseal lamina fossa), it is not able to be referred unequivocally to Austrosaurus and is retained as Titanosauriformes indet. Austrosaurus mckillopi is one of the oldest known sauropods from the Australian Cretaceous based on skeletal remains and potentially provides phylogenetic and/or palaeobiogeographic context for later taxa such as Wintonotitan wattsi, Diamantinasaurus matildae and Savannasaurus elliottorum.

Fig. 11. Reconstruction of the possible sequence of events that led to the preservation of the carcass of the sauropod Austrosaurus mckillopi in the Eromanga Sea. (A) Austrosaurus as a living animal on land; (B) freshly deceased Austrosaurus prior to bloating; (C) bloated Austrosaurus carcass washed out to sea, where it was possibly scavenged by marine reptiles like Kronosaurus; (D) the partially defleshed but still effectively intact thoracic portion of the Austrosaurus carcass is picked at by sharks as it sinks to the seafloor; (E) the thoracic portion of the Austrosaurus carcass is buried along with several ammonites (Beudanticeras) and bivalves (Inoceramus), which were possibly drawn to the carcass as it decayed.

Reconstruction by Travis R. Tischler. 

Conclusion: 

The sauropod taxon Austrosaurus mckillopi is of historical significance to Australian palaeontology as the first Cretaceous dinosaur recognized in Queensland, and the first Cretaceous sauropod ever reported from the entire continent. The augmentation, articulation and description of the type material have helped to shed light on the phylogenetic position of Austrosaurus, unequivocally placing it within Titanosauriformes, and probably as a member of Somphospondyli. The identification of an autapomorphic auxiliary pneumatic foramen in dorsal vertebra I means that the referral of other sauropod specimens to Austrosaurus should be possible in the future, although this feature is not presently observable in any other Australian sauropod specimen. The morphological congruence of the posteriormost cervical vertebra of Austrosaurus with QM F6142 (the ‘Hughenden sauropod’) might represent grounds for the referral of the latter to the former, although this can not be demonstrated unequivocally. Lastly, despite its fragmentary nature, Austrosaurus appears to share several features with the type specimens of both Diamantinasaurus and Savannasaurus, possibly indicating a close phylogenetic relationship.

The fragmentary nature of the type series of Austrosaurus has impeded, and will continue to restrict, efforts to precisely resolve its phylogenetic position within Titanosauriformes. Consequently, the palaeobiogeographic significance of Austrosaurus is poorly understood, a situation worsened by the relative rarity of Early Cretaceous titanosauriforms in South America and the lack of such in Antarctica. Nevertheless, the presence of numerous titanosauriform lineages in the Early Cretaceous of South America provides some context for Australian Early Cretaceous titanosauriforms like Austrosaurus, and also for the mid-Cretaceous Winton Formation fauna, which appears to have been dominated by titanosaurs with amphicoelous (rather than procoelous) caudal vertebrae.

Stephen F. Poropat, Jay P. Nair, Caitlin E. Syme, Philip D. Mannion, Paul Upchurch, Scott A. Hocknull,  Alex G. Cook, Travis R. Tischler and Timothy Holland. 2017. Reappraisal of Austrosaurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s First Named Cretaceous Sauropod Dinosaur. Alcheringa: An Australasian Journal of Palaeontology. DOI: 10.1080/03115518.2017.1334826

twitter.com/taphovenatrix/status/890381395851304960/photo

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.

[Paleontology • 2017] Ostromia crassipes [gen. nov.] • Re-evaluation of the Haarlem Archaeopteryx and the Radiation of Maniraptoran Theropod Dinosaurs ---ScRaBBlE

Ostromia crassipes (Meyer, 1857)

 “Haarlem specimen”, holotype of Ostromia crassipes (Meyer, 1857).
Counterslab, Teylers Museum TM 6929 (left) and main slab, TM 6928 (right).

Foth & Rauhut, 2017.  DOI:  10.1186/s12862-017-1076-y

Abstract

Background

Archaeopteryx is an iconic fossil that has long been pivotal for our understanding of the origin of birds. Remains of this important taxon have only been found in the Late Jurassic lithographic limestones of Bavaria, Germany. Twelve skeletal specimens are reported so far. Archaeopteryx was long the only pre-Cretaceous paravian theropod known, but recent discoveries from the Tiaojishan Formation, China, yielded a remarkable diversity of this clade, including the possibly oldest and most basal known clade of avialan, here named Anchiornithidae. However, Archaeopteryx remains the only Jurassic paravian theropod based on diagnostic material reported outside China.

Results

Re-examination of the incomplete Haarlem Archaeopteryx specimen did not find any diagnostic features of this genus. In contrast, the specimen markedly differs in proportions from other Archaeopteryx specimens and shares two distinct characters with anchiornithids. Phylogenetic analysis confirms it as the first anchiornithid recorded outside the Tiaojushan Formation of China, for which the new generic name Ostromia is proposed here.

Conclusions

In combination with a biogeographic analysis of coelurosaurian theropods and palaeogeographic and stratigraphic data, our results indicate an explosive radiation of maniraptoran coelurosaurs probably in isolation in eastern Asia in the late Middle Jurassic and a rapid, at least Laurasian dispersal of the different subclades in the Late Jurassic. Small body size and, possibly, a multiple origin of flight capabilities enhanced dispersal capabilities of paravian theropods and might thus have been crucial for their evolutionary success.

Keywords: Maniraptora, Anchiornithidae, Late Jurassic, Biogeography, Radiation

Fig. 1 Overview of the “Haarlem specimen”, holotype of Ostromia crassipes (Meyer, 1857). Counterslab, Teylers Museum TM 6929 (left) and main slab, TM 6928 (right). 

Systematic Palaeontology

Theropoda Marsh, 1881  

Maniraptora Gauthier, 1986 

Anchiornithidae tax. Nov.

Type genus. Anchiornis 

Xu, Zhao, Norell, Sullivan, Hone, Erickson, Wang, Han, and Gao, 2009  

Definition. Anchiornithidae is a stem-based taxon defined as all maniraptoran theropods that are more closely related to Anchiornis huxleyi than to Passer domesticus, Archaeopteryx lithographica, Dromaeosaurus albertensis, Troodon formosus, or Oviraptor philoceratops.

Ostromia gen. nov.

Ostromia crassipes von Meyer, 1857  

Holotype. Teylers Museum TM 6928, 6929, part and counterpart of a fragmentary skeleton.

Locality and horizon. Jachenhausen locality, near Riedenburg, Bavaria, Germany. Early Tithonian laminated limestones of the Painten Formation.

Etymology. The generic name honours the late John Ostrom, who identified the Haarlem specimen as a theropod.

Conclusions

A re-evaluation of one of the twelve skeletal specimens referred to the ‘Urvogel’ Archaeopteryx, the Haarlem specimen, revealed that this specimen represents a separate taxon, Ostromia crassipes. Phylogenetic analysis identifies Ostromia as the first representative of the basal avialian clade Anchiornithidae outside eastern Asia. In combination with a biogeographic analysis, a rapid radiation of maniraptoran theropods in eastern Asia with a subsequent dispersal of many lineages in the Late Jurassic is indicated; dispersal of maniraptorans was facilitated by small body size of basal members of all clades and, possibly, several independent acquisitions of flight capabilities. In the fragmenting world of Pangean break-up during the Late Jurassic and Cretaceous, increased dispersal potential might have been a key factor to explain the success of maniraptoran, and especially avialian theropods, with dispersal events being followed by endemic radiations of different clades.

Christian Foth and Oliver W. M. Rauhut. 2017. Re-evaluation of the Haarlem Archaeopteryx and the Radiation of Maniraptoran Theropod Dinosaurs. BMC Evolutionary Biology.   17:236. DOI:  10.1186/s12862-017-1076-y

 

Groot nieuws! De beroemde #Archaeopteryx van Teylers Museum blijkt nog ouder dan gedacht en wereldwijd uniek te zijn. Het is een fossiel van een nieuw ontdekte dinosaurussoort met veren, die de naam Ostromia heeft gekregen. #breakingnews http://bit.ly/2jdITeB  @TEYLERS

Paleontologists at LMU correct a case of misinterpretation: The first fossil “Archaeopteryx” to be discovered is actually a predatory dinosaur belonging to the anchiornithid family, which was previously known only from finds made in China: http://www.en.uni-muenchen.de/news/newsarchiv/2017/rauhut_archaeopteryx.html … @LMU_Muenchen

 xinglida.net/Museum/Archaeopteryx.htm

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روابط التحميل والمشاهدة، الروابط المباشرة للتحميل

من هنا

او

من هنا

شاهد هذا الفيديو القصير لطريقة التحميل البسيطة

منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات

كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا

شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا

رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا
شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا

تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا

ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.